MIAMI, Sept 23 (AFP) Sep 23, 2011Hurricane Hilary swelled to a Category Four storm on Friday but was moving away from Mexico's Pacific coast and was not expected to strike land, according to the US-based National Hurricane Center.

Packing winds of 145 miles (230 kilometers) per hour, the storm was 125 miles (200 kilometers) southwest of the resort town of Zihuantenejo, the NHC said.

Hilary was moving into the open Pacific at a speed of 10 miles (16 kilometers) per hour, the NHC said in its 1200 GMT bulletin.

"On the forecast track, the core of Hilary should continue moving farther offshore of the southwestern coast of Mexico today," the NHC said.

Mexican authorities warned that tropical storm-force winds and heavy surf could affect the coast, but Hilary was not expected to make landfall.

Hilary is expected to drop between three and five inches (7.6 to 13 centimeters) across parts of southern Mexico, "with isolated amounts of 10 inches possible," the NHC said.

Large swells generated by Hilary "are likely causing life-threatening surf and rip current conditions" are affecting parts of the coast, it said.

Despite it's wind speed, Hilary remains a small storm: hurricane-force winds extend outward just up to 25 miles (35 kilometers) from the center, and tropical storm force winds extend outward up to 80 miles (130 kilometers).